U.S. patent application number 12/882243 was filed with the patent office on 2012-03-15 for phacoemulsification hand piece with two independent transducers.
This patent application is currently assigned to Alcon Research, Ltd.. Invention is credited to Jiansheng Zhou.
Application Number | 20120065578 12/882243 |
Document ID | / |
Family ID | 45807395 |
Filed Date | 2012-03-15 |
United States Patent
Application |
20120065578 |
Kind Code |
A1 |
Zhou; Jiansheng |
March 15, 2012 |
Phacoemulsification Hand Piece with Two Independent Transducers
Abstract
An ophthalmic surgical hand piece has a horn and two
transducers. The horn has a central axis. A flange having a
generally flat surface is coupled to the horn. The flange extends
radially from the horn and generally perpendicular to the central
axis. A first ear having a generally flat surface is coupled to the
horn. The first ear extends from the horn such that the generally
flat surface of the first ear is generally perpendicular to the
generally flat surface of the flange. A first transducer is held
against the flange, and a second transducer held against the
ear.
Inventors: |
Zhou; Jiansheng; (Irvine,
CA) |
Assignee: |
Alcon Research, Ltd.
|
Family ID: |
45807395 |
Appl. No.: |
12/882243 |
Filed: |
September 15, 2010 |
Current U.S.
Class: |
604/22 |
Current CPC
Class: |
A61F 9/00745 20130101;
A61M 1/0064 20130101 |
Class at
Publication: |
604/22 |
International
Class: |
A61F 9/007 20060101
A61F009/007 |
Claims
1. An ophthalmic surgical hand piece comprising: a horn with a
central axis; a flange coupled to the horn, the flange having a
generally flat surface, the flange extending from the horn and
generally perpendicular to the central axis; a first ear coupled to
the horn, the first ear having a generally flat surface, the first
ear extending from the horn such that the generally flat surface of
the first ear is generally perpendicular to the generally flat
surface of the flange; a first transducer held against the flange;
and a second transducer held against the first ear.
2. The hand piece of claim 1 wherein the first and second
transducers are capable of vibrating in a longitudinal direction,
the first transducer imparts a longitudinal vibration to the horn,
and the second transducer imparts a torsional or twisting vibration
to the horn.
3. The hand piece of claim 1 further comprising: a second ear
coupled to the horn, the second ear having a generally flat
surface, the second ear extending from the horn such that the
generally flat surface of the second ear is generally perpendicular
to the generally flat surface of the flange.
4. The hand piece of claim 3 wherein the second ear is located
generally opposite the first ear on the horn.
5. The hand piece of claim 3 further comprising: a third transducer
held against the second ear.
6. The hand piece of claim 1 further comprising: a needle coupled
to the horn.
7. The hand piece of claim 1 further comprising: a first pair of
lead wires electrically coupled to the first transducer; and a
second pair of lead wires electrically coupled to the second
transducer; wherein driving voltages can be independently applied
to the first transducer via the first pair of lead wires and to the
second transducer via the second pair of lead wires.
8. The hand piece of claim 1 further comprising: a shell enclosing
the horn, first transducer, and second transducer.
9. The hand piece of claim 1 wherein the flange is generally
disc-shaped.
10. The hand piece of claim 1 wherein the ear is generally
rectangular in shape.
11. The hand piece of claim 1 wherein the horn is generally
cylindrical in shape.
12. The hand piece of claim 1 wherein the horn further comprises a
lumen that extends through the horn along the central axis.
13. The hand piece of claim 1 wherein the second transducer is held
against the first ear at an angle.
14. An ophthalmic surgical hand piece comprising: a horn with a
central axis; a flange coupled to the horn, the flange having a
first surface generally perpendicular to the central axis and a
second surface generally parallel to the central axis; a first ear
coupled to the horn, the first ear having a generally flat surface,
the first ear extending from the horn such that the generally flat
surface of the first ear is generally parallel to the second
surface of the flange; a first transducer held against the first
surface of the flange; and a second transducer held between the
first ear and the second surface of the flange.
15. The hand piece of claim 14 wherein the first and second
transducers are capable of vibrating in a longitudinal direction,
the first transducer imparts a longitudinal vibration to the horn,
and the second transducer imparts a torsional or twisting vibration
to the horn.
16. The hand piece of claim 14 further comprising: a second ear
coupled to the horn, the second ear having a generally flat
surface, the second ear extending from the horn such that the
generally flat surface of the second ear is generally parallel to
the second surface of the flange.
17. The hand piece of claim 16 wherein the second ear is located
generally opposite the first ear on the horn.
18. The hand piece of claim 17 further comprising: a third
transducer held against the second ear.
19. The hand piece of claim 14 further comprising: a first pair of
lead wires electrically coupled to the first transducer; and a
second pair of lead wires electrically coupled to the second
transducer; wherein driving voltages can be independently applied
to the first transducer via the first pair of lead wires and to the
second transducer via the second pair of lead wires.
20. The hand piece of claim 14 wherein the second transducer is
held against the first ear at an angle.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to phacoemulsification surgery
and more particularly to phacoemulsification hand piece that is
capable of imparting both longitudinal and torsional motion to a
cutting tip.
[0002] The human eye functions to provide vision by transmitting
light through a clear outer portion called the cornea, and focusing
the image by way of a crystalline lens onto a retina. The quality
of the focused image depends on many factors including the size and
shape of the eye, and the transparency of the cornea and the lens.
When age or disease causes the lens to become less transparent,
vision deteriorates because of the diminished light which can be
transmitted to the retina. This deficiency in the lens of the eye
is medically known as a cataract. An accepted treatment for this
condition is surgical removal of the lens and replacement of the
lens function by an artificial intraocular lens (IOL).
[0003] In the United States, the majority of cataractous lenses are
removed by a surgical technique called phacoemulsification. A
typical surgical hand piece suitable for phacoemulsification
procedures consists of an ultrasonically driven phacoemulsification
hand piece, an attached hollow cutting needle surrounded by an
irrigating sleeve, and an electronic control console. The hand
piece assembly is attached to the control console by an electric
cable and flexible tubing. Through the electric cable, the console
varies the power level transmitted by the hand piece to the
attached cutting needle. The flexible tubing supplies irrigation
fluid to the surgical site and draws aspiration fluid from the eye
through the hand piece assembly.
[0004] The operative part in a typical hand piece is a centrally
located, hollow resonating bar or horn directly attached to a set
of piezoelectric crystals. The crystals supply the required
ultrasonic vibration needed to drive both the horn and the attached
cutting needle during phacoemulsification, and are controlled by
the console. The crystal/horn assembly is suspended within the
hollow body or shell of the hand piece by flexible mountings. The
hand piece body terminates in a reduced diameter portion or
nosecone at the body's distal end. Typically, the nosecone is
externally threaded to accept the hollow irrigation sleeve, which
surrounds most of the length of the cutting needle. Likewise, the
horn bore is internally threaded at its distal end to receive the
external threads of the cutting tip. The irrigation sleeve also has
an internally threaded bore that is screwed onto the external
threads of the nosecone. The cutting needle is adjusted so that its
tip projects only a predetermined amount past the open end of the
irrigating sleeve.
[0005] During the phacoemulsification procedure, the tip of the
cutting needle and the end of the irrigation sleeve are inserted
into the anterior capsule of the eye through a small incision in
the outer tissue of the eye. The surgeon brings the tip of the
cutting needle into contact with the lens of the eye, so that the
vibrating tip fragments the lens. The resulting fragments are
aspirated out of the eye through the interior bore of the cutting
needle, along with irrigation solution provided to the eye during
the procedure, and into a waste reservoir.
[0006] Power is applied to the hand piece to vibrate the cutting
needle. In general, the amplitude of needle movement (or vibration)
is proportional to the power applied. In conventional
phacoemulsification systems, the needle vibrates back and forth
producing a longitudinal needle stroke. In improved systems, the
needle may be caused to vibrate in a twisting or torsional motion.
One way to achieve twisting or torsional motion is described in
U.S. Pat. No. 7,651,490. Twisting or torsional motion of the
cutting tip has proven a very effective way of removing lens
material. Twisting or torsional movement of the cutting tip avoids
repulsion that can occur with traditional longitudinal movement of
the cutting tip and leads to more effective lens removal. In other
instances, longitudinal motion may be used to clear an occluded tip
by pushing the lens material away from the tip. As such, during
cataract surgery both longitudinal and torsional or twisting motion
may be desirable depending on the circumstances. Moreover, it may
also be desirable to have both types of motion at the cutting tip
simultaneously.
SUMMARY OF THE INVENTION
[0007] In one embodiment consistent with the principles of the
present invention, the present invention is an ophthalmic surgical
hand piece having a horn and two transducers. The horn has a
central axis. A flange having a generally flat surface is coupled
to the horn. The flange extends radially from the horn and
generally perpendicular to the central axis. A first ear having a
generally flat surface is coupled to the horn. The first ear
extends from the horn such that the generally flat surface of the
first ear is generally perpendicular to the generally flat surface
of the flange. A first transducer is held against the flange, and a
second transducer held against the ear.
[0008] In another embodiment consistent with the principles of the
present invention, the present invention is an ophthalmic surgical
hand piece having a horn with a central axis. A flange is coupled
to the horn. The flange has a first surface generally perpendicular
to the central axis of the horn and a second surface generally
parallel to the central axis of the horn. A first ear is coupled to
the horn. The first ear has a generally flat surface extending from
the horn such that the generally flat surface of the first ear is
generally parallel to the second surface of the flange. A first
transducer is held against the first surface of the flange. A
second transducer held between the first ear and the second surface
of the flange.
[0009] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are intended to provide further
explanation of the invention as claimed. The following description,
as well as the practice of the invention, set forth and suggest
additional advantages and purposes of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate several
embodiments of the invention and together with the description,
serve to explain the principles of the invention.
[0011] FIG. 1 is a diagram of the components in the fluid path of a
phacoemulsification system.
[0012] FIGS. 2A-2D are perspective views of the distal end of a
phacoemulsification needle and irrigation sleeve according to the
principles of the present invention.
[0013] FIG. 3 is a perspective view of a horn and needle assembly
according to the principles of the present invention.
[0014] FIG. 4 is a perspective view of a horn according to the
principles of the present invention.
[0015] FIGS. 5A and 5B are diagrams of two embodiments of a
transducer and horn according to the principles of the present
invention.
[0016] FIGS. 6A and 6B are diagrams of two embodiments of a
transducer and horn according to the principles of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Reference is now made in detail to the exemplary embodiments
of the invention, examples of which are illustrated in the
accompanying drawings. Wherever possible, the same reference
numbers are used throughout the drawings to refer to the same or
like parts.
[0018] In one embodiment of the present invention, FIG. 1 is a
diagram of the components in the fluid path of a
phacoemulsification system. FIG. 1 depicts the fluid path through
the eye 1145 during cataract surgery. The components include an
irrigation fluid source 1105, an irrigation pressure sensor 1130,
an irrigation valve 1135, an irrigation line 1140, a hand piece
1150, an aspiration line 1155, an aspiration pressure sensor 1160,
a vent valve 1165, a pump 1170, a reservoir 1175 and a drain bag
1180. The irrigation line 1140 provides irrigation fluid to the eye
1145 during cataract surgery. The aspiration line 1155 removes
fluid and emulsified lens particles from the eye during cataract
surgery.
[0019] When irrigation fluid exits irrigation fluid source 1105, it
travels through irrigation line 1140 and into the eye 1145. An
irrigation pressure sensor 1130 measures the pressure of the
irrigation fluid in irrigation line 1140. An optional irrigation
valve 1135 is also provided for on/off control of irrigation.
Irrigation pressure sensor 1130 is implemented by any of a number
of commercially available fluid pressure sensors and can be located
anywhere in the irrigation fluid path (anywhere between the
irrigation source 1105 and the eye 1145).
[0020] A hand piece 1150 is placed in the eye 1145 during a
phacoemulsification procedure. The hand piece 1150 has a hollow
needle (as seen in FIG. 2) that is ultrasonically vibrated in the
eye to break up the diseased lens. A sleeve located around the
needle provides irrigation fluid from irrigation line 1140. The
irrigation fluid passes through the space between the outside of
the needle and the inside of the sleeve (as more clearly shown in
FIG. 2A). Fluid and lens particles are aspirated through the hollow
needle. In this manner, the interior passage of the hollow needle
is fluidly coupled to aspiration line 1155. Pump 1170 draws the
aspirated fluid from the eye 1145. An aspiration pressure sensor
1160 measures the pressure in the aspiration line. An optional vent
valve can be used to vent the vacuum created by pump 1170. The
aspirated fluid passes through reservoir 1175 and into drain bag
1180.
[0021] FIG. 2A is a perspective view of the distal end of a
phacoemulsification hand piece according to the principles of the
present invention. In FIG. 2, a phacoemulsification needle 1210 is
surrounded by an irrigation sleeve 1230. The phacoemulsification
needle 1210 has an open end 1220 through which lens particles are
aspirated from the eye during cataract surgery. The irrigation
sleeve 1230 has an optional opening 1240 through which irrigation
fluid flows into the eye. The needle 1210 and sleeve 1230 are both
inserted into the anterior chamber of the eye during cataract
surgery. When power is applied to the hand piece, the needle 1210
vibrates ultrasonically in a longitudinal mode, a torsional mode,
or in both modes simultaneously. This is more clearly seen in FIGS.
2B-2D. In FIG. 2B, needle 1210 vibrates in longitudinal mode (back
and forth). In FIG. 2C, needle 1210 vibrates in torsional mode (or
in a twisting or sweeping manner). In FIG. 2D, needle 1210 vibrates
in both longitudinal and torsional modes simultaneously.
[0022] The two different modes (longitudinal and torsional) produce
two different needle motions as shown in FIGS. 2B-2D. In general,
longitudinal mode can act to cut a cataractous lens by impacting
the end of the needle 1210 against the lens much like a jackhammer.
Torsional mode can act to cut a lens with a side to side sweep of
the end of the needle 1210. Depending on the needle geometry, the
twisting motion imparted to the needle 1210 in torsional mode
generally produces a side to side sweep of the end of the needle
1210. In other instances, the end of the needle 1210 sweeps in an
arc. Regardless, torsional mode may be more effective in cutting a
lens because it allows aspiration through open end 1220 of needle
1210 to hold the lens material on the needle 1210 for more
effective cutting. In addition, in torsional mode, each sweep of
the needle 1210 acts to cut the lens. In contrast, longitudinal
mode produces a jack hammer motion that impacts the lens only in a
forward direction (and not in a return direction). Moreover,
longitudinal mode may act to repel the lens material away from the
needle which may reduce cutting efficiency. However, when the open
end 1220 of the needle 1210 is occluded or blocked by lens
material, the repulsion effect of longitudinal mode may be
effective at clearing the material which can be desirable.
[0023] When both modes are operated simultaneously, the needle 1210
moves both longitudinally and torsionally at the same time. The
amount of longitudinal and torsional motion can be controlled
independently as explained below. In some instances, this
combination motion may be more effective at cutting the lens and/or
clearing lens material from the open end 1220 of needle 1210.
[0024] FIG. 3 is a perspective view of a horn and needle assembly
according to the principles of the present invention. In FIG. 3,
horn 1300 has a flange 1310, and two ears 1320 and 1321. A needle
1210 with an open end 1220 is coupled to horn 1300 via hub 1340.
Needle 1210 is typically coupled to horn 1300 via a threaded
connection at hub 1340. The horn 1300 is coupled to one or more
transducers as shown in FIGS. 4, 5A, and 5B. Horn 1300 is typically
made of a solid material such as a titanium alloy. One or more
transducers produce vibrations which are imparted to horn 1300. As
horn 1300 vibrates, needle 1210 also vibrates. In this manner, if
horn 1300 is vibrated longitudinally, then needle 1210 also
vibrates longitudinally. Likewise, if horn 1300 vibrates
torsionally, then needle 1210 also vibrates torsionally.
[0025] The assembly shown in FIG. 3 is a part of a larger
phacoemulsification hand piece. The horn 1300 and associated
transducer(s) are held within a hand piece shell (not shown). The
hand piece shell is of a form factor suitable to be held in the
hand and manipulated by a surgeon during cataract surgery. As such,
the shell is typically about the size of a large pencil or pen. The
needle 1210 and hub 1340 typically extend from one end of the hand
piece shell (not shown). In this manner, the needle 1210 (and
irrigation sleeve) can be inserted into the eye and vibrated
ultrasonically to fragment the lens.
[0026] Horn 1300 may be machined from a single piece of material.
Flange 1310 extends radially from the horn's central body as shown
in FIG. 3. In this example, flange 1310 is in the general shape of
a disc, though it may be other shapes. Flange 1310 is arranged such
that one or more transducers can be held against it. Likewise, ears
1320 and 1321 extend outward from the horn's central body as shown
in FIG. 3. In this example, ears 1320 and 1321 are generally square
or rectangular in shape, though they may be of other shapes. Ears
1320 and 1321 are arranged so that one or more transducers can be
held against them.
[0027] FIG. 4 shows a horn and transducer assembly according to the
principles of the present invention. In the example of FIG. 4, horn
1300 has a flange 1310 and two ears 1320 and 1321. A lumen 1330
extends through horn 1300. Aspirated lens material flows through
lumen 1330. In this manner, lumen 1330 is coextensive with the
internal lumen of needle 1210 (when needle 1210 is coupled to horn
1300). As such, when needle 1210 fragments lens material, that lens
material can be aspirated through the internal lumen of needle 1210
and lumen 1330 of horn 1300.
[0028] Transducer 1400 is held against flange 1310 such that
vibration produced by transducer 1400 results in vibration of horn
1300 (and needle 1210 when needle 1210 is coupled to horn 1300). In
FIG. 4, transducer 1400 vibrates longitudinally (back and forth).
Since transducer 1400 is held against flange 1310 (which is a part
of horn 1300), horn 1300 also vibrates longitudinally.
Consequently, a needle attached to horn 1300 would also vibrate
longitudinally. In this manner, transducer 1400, when activated,
operates the hand piece in longitudinal mode.
[0029] As shown in FIGS. 5A and 5B, transducers 1410 and 1420 are
held against ears 1320 and 1321. Transducers 1410 and 1420 vibrate
longitudinally (back and forth). Since transducers 1410 and 1420
are held against ears 1320 and 1321, horn 1300 is caused to vibrate
torsionally or in a twisting or rotating manner. This torsional or
twisting movement of horn is produced as the transducers 1410 and
1420 press against ears 1320 and 1321 causing a partial rotation of
horn 1300. In this manner, transducers 1410 and 1420 produce
vibration that is generally orthogonal to the vibration produced by
transducer 1400. A needle coupled to horn 1300 would also vibrate
torsionally or in a twisting fashion (i.e. in torsional mode).
Typically, transducers 1400, 1410, and 1420 are piezoelectric
crystals which are commonly used in ophthalmic ultrasound hand
pieces.
[0030] In FIG. 5A, transducers 1410 and 1420 are held flush against
ears 1320 and 1321. In FIG. 5B, transducers 1410 and 1420 are held
at an angle against ears 1320 and 1321. Since transducers 1410 and
1420 vibrate longitudinally and ears 1320 and 1321 can only rotate
about the central axis of horn 1300, either of these two
configurations can produce sufficient torsional or twisting motion
of horn 1300 and an attached needle.
[0031] To achieve torsional or twisting motion of horn 1300 and
attached needle 1210, the transducers 1410 and 1420 move
longitudinally to cause a rotation of ears 1320 and 1321 about the
central axis of horn 1300. In FIG. 5B, the transducers 1410 and
1420 may be held at an angle equal to one half of the targeted ear
rotation angle. In this way, when the transducers 1410 and 1420
move the ears 1320 and 1321 to the targeted rotation angle, the
maximum angle between the transducers 1410 and 1420 and the ears
1320 and 1321 would only be one half of the targeted ear rotation
angle. In contrast, in FIG. 5A, the angle between the transducers
1410 and 1420 and the ears 1320 and 1321, respectively, would be
the full ear rotation angle. In this manner, the angle between the
transducers 1410 and 1420 and the ears 1320 and 1321, respectively,
in FIG. 5A is greater than the angle between the transducers 1410
and 1420 and the ears 1320 and 1321, respectively, in FIG. 5B. The
reduced angle in FIG. 5B results in less stress on the transducers
1410 and 1420 which may prevent them from cracking.
[0032] FIGS. 6A and 6B are diagrams of two embodiments of a
transducer and horn according to the principles of the present
invention. In FIGS. 6A and 6B, transducers 1410 and 1420 are held
against ears 1320 and 1321 by a flange 1510 that is integral with
or coupled to horn 1300. In FIGS. 6A and 6B, transducer 1400 is
held between torque ring 1520 and flange 1510. A nut 1530 secures
torque ring 1520 and transducer 1400 against flange 1510. In this
manner, when transducer 1400 vibrates, horn 1300 also vibrates.
[0033] FIG. 6B shows the location of transducers 1410 and 1420.
Transducer 1410 is held between flange 1510 and ear 1320. Likewise,
transducer 1420 is held between flange 1510 and ear 1321 (not
shown). While shown as being held flush against ear 1320,
transducer 1410 may be held at an angle against ear 1320 in a
manner similar to that depicted in FIG. 5B. Likewise, transducer
1420 may be held at an angle against ear 1321 in a manner similar
to that depicted in FIG. 5B.
[0034] In the embodiment of FIGS. 6A and 6B, flange 1510 may be
generally planar as shown or may have a radius of curvature about
the central axis of horn 1300 (i.e. the axis along the lumen 1330
of horn 1300). In this example, transducers 1410 and 1420 are
fitted in horn 1300. When transducers 1410 and 1420 vibrate, the
vibration is localized at horn 1300. When transducer 1400 vibrates,
the transducers 1410 and 1420 move with the flange 1510, ear 1320,
and ear 1321.
[0035] While transducers 1400, 1410, and 1420 are shown on
different figures, all three transducers may be employed in a
single assembly. In this manner, all three transducers can be
activated to vibrate the needle in longitudinal mode and torsional
mode simultaneously. In addition, since transducers 1400, 1410, and
1420 can each be operated separately, the amount of torsional and
longitudinal motion imparted to a needle can be precisely
controlled. Transducers 1400, 1410, and 1420 are each typically
driven by a voltage or current source. Generally, the amount of
voltage (or power) applied to each transducer 1400, 1410, and 1420
determine its amplitude of vibration. The higher the voltage
applied, the greater the amplitude of vibration. By controlling the
voltage (or power) applied to each transducer individually, the
amount of longitudinal and torsional vibration can be precisely
controlled. The voltages (or power) applied to transducers 1400,
1410 and 1420 may be applied, for example, via lead wires coupled
to the transducers.
[0036] For example, transducer 1400 may be driven with a low
voltage that produces a small amount of longitudinal vibration in
the horn 1300 and attached needle 1210. At the same time, a greater
voltage can be applied to transducers 1410 and 1420 to produce a
relatively large amount of torsional or twisting vibration in horn
1300 and attached needle 1210. Expressed as a percentage of maximum
vibration, this example may yield 10% longitudinal vibration and
90% torsional vibration. In this manner, if all transducers 1400,
1410, and 1420 are driven at their maximum voltages, then the
longitudinal vibration is 100% and the torsional vibration is also
100%. By adjusting the driving voltages for each transducer, any
combination of percentages can be produced. This manner of
operating the hand piece may be beneficial in that precise amounts
and types of vibration can be applied to the needle 1210 to produce
a desired cutting effect.
[0037] From the above, it may be appreciated that the present
invention provides an improved hand piece for phacoemulsification
surgery. The present invention provides a horn that is designed to
impart longitudinal and torsional motion to a cutting tip
simultaneously and in any proportion. The present invention is
illustrated herein by example, and various modifications may be
made by a person of ordinary skill in the art.
[0038] Other embodiments of the invention will be apparent to those
skilled in the art from consideration of the specification and
practice of the invention disclosed herein. It is intended that the
specification and examples be considered as exemplary only, with a
true scope and spirit of the invention being indicated by the
following claims.
* * * * *